Various sources of 3D video information are well known. For High Definition movie publishing, the Blu-ray disc system is widely used. Initially the BD-ROM audio-visual application format only contained support for 2D video. Various video coding options are included in the system, which are all supported by BD-ROM compliant playback devices. One of the supported video codecs is AVC (also known as ISO/IEC MPEG-4 Part 10 and ITU-T H.264). Recently the Blu-ray video distribution system was extended with stereoscopic 3D capabilities based on the Stereo High profile of MVC (Multiview Video Coding), an extension of AVC. The Blu-ray Stereoscopic 3D (S3D) extension is currently restricted to progressive video. Two progressive video modes are defined for BD3D: 1080 line mode at 24 (actually 23.976) frames per second (“1080p24”) and 720 line mode at 50 or 60 (actually 59.94) frames per second. For S3D, the video stream is composited of a so-called independent view and a dependent view. The independent view is AVC compliant and can potentially be decoded by BD players that are not designed to decode the full BD3D (MVC) video stream. Background information on the Blu-ray Disc Read-Only Audio Visual Application format can be found in a White Paper published by the Blu-ray Disc Association: http://www.blu-raydisc.com/assets/Downloadablefile/BD-ROM-AV-WhitePaper_110712.pdf An overview of the BD3D extension is described in section 6, while details can be found in Annex A of this White Paper.
The MVC format and the way it has been applied in Blu-ray enable the disc author to create S3D Blu-ray discs such that they can be played as 2D video on players that do not support stereoscopic playback, or in the case that the connected display does not support 3D display. To be able to select either 2D playback or S3D playback, the playback program information contains branches with playback instructions and settings for both options. The playback program has access to a set of 32-bit Player Setting Registers and Playback Status Registers (referred to as PSRs) that can be used to adapt e.g. playlist selection or playback options. For the extension of the Blu-ray format with S3D capabilities, additional PSRs were defined, including a PSR to indicate display capabilities. These display capabilities include a field to contain the horizontal display size, a bit to indicate whether or not glasses are required for stereoscopic display and a bit to indicate if the display is capable of displaying stereoscopic content. The playback program can for instance read the bit that indicates the stereoscopic capability of the display and select either the 2D or the S3D branch depending on the value.
A 3D video processing device like a BD player or set top box may be coupled to a 3D display device like a TV set or monitor for transferring the 3D video data via a display signal on suitable interface, preferably a high-speed digital interface like HDMI. High definition pixel data is transmitted along with audio from the source to the destination device. In addition to that, HDMI can carry data in both directions, e.g. for control purposes and to exchange status information. There is a possibility for the so-called EDID (Extended Display Identification Code), which allows a display to show its capabilities to a source device like a BD player. These EDID capability parameters include the various combinations of spatial resolutions and frame rates supported by the display.
The 3D display device receives a 3D display signal via the interface and provides different images to the respective eyes of a viewer to create a 3D effect. The display device may be a stereoscopic device, e.g. for a viewer wearing shutter glasses that pass left and right views displayed sequentially to the respective left and right eye of a viewer. However, the display device may also be an auto stereoscopic display that generates multiple views; different views being perceived by the respective eyes of a viewer not wearing glasses.
The invention is focused on the specific type of interlaced video data. Traditionally interlaced video data signals transfer even lines and odd lines of a video frame in two separate sets, usually called fields. Also for 3D video data various interlaced 3D display formats have been proposed, for example in the HDMI standard version 1.4a. The relevant part relating to 3D is described in the document “High-Definition Multimedia Interface, Specification Version 1.4a, Extraction of 3D Signaling Portion” of Mar. 4, 2010, available from http://www.hdmi.org/, which document describes the respective high resolution and lower resolution interlaced 3D formats as discussed further below.
When HDMI was extended to support 3D formats, two methods were defined to transmit stereoscopic (2-view) 3D. One method is to use the existing 2D format and to squeeze the two views (left and right) of stereoscopic video into the 2D format. Within this method there are 2 options: the side-by side configuration and the top-bottom configuration. The other method is to double the number of video lines of an HDMI video frame and to transmit the 2 full HD views subsequently (L first) in this single HDMI frame. The latter method is called “frame packed”.
HDMI defines a number of mandatory 3D formats. There are only 2 mandatory frame packing formats: 1080p24 and 720p50/60. These coincide with the Blu-ray S3D progressive video formats. The side-by-side and top-bottom formats do not provide a full resolution per eye quality, but they match 3D formats selected by broadcasters in various countries, having the advantage that existing AVC decoders designed for Full HD can be used to decode “frame compatible” (side-by-side or top-bottom) 3D video signals. These frame compatible formats include interlace video modes, as for broadcasting interlaced video is widely used.
US2009/0284652 describes a video processing system (VPS) that receives a plurality of video inputs and specifically tailors them to meet the audio/video format requirements of a plurality of recipient video devices. The VPS may query the recipient devices to obtain the audio/video format requirements of the video devices. Reformatting may involve transcoding the input signals to produce output video formats as needed. Multiple VPS may exchange information regarding their conversion capabilities, and an appropriate VPS may automatically be selected.